Capturing instances when a vehicle travels above a posted speed limit, (i.e. a speeding exception), is an important factor in managing a fleet of vehicles. Accurate information regarding speeding exceptions may improve assessments on insurance rates, and may enable a fleet manager to improve fuel consumption, and safety and compliance. Methods of determining the speed a vehicle is traveling, (i.e. the indicated speed) are known. However, accurate methods of determining the speed that governed the vehicle (i.e. the posted speed), when the vehicle was traveling the indicated speed, are not known.
Traditionally two approaches have been taken to determine if speeding exceptions have occurred. One is to set a threshold posted speed for all travel. For example, a threshold posted speed of 70 mph may be chosen. In this example, only if a vehicle is traveling over 70 mph will an exception be registered. This method does not accurately assess speeding exceptions because it does not take into account the actual posted speed. For instance, if the posted speed limit is 35 mph, and the vehicle is traveling at an indicated speed of 65 mph, a notable instance of speeding will not be registered because the indicated speed is below 70 mph. Conversely, if the vehicle is traveling at an indicated speed of 72 mph and the posted speed limit is 70 mph, a speeding exception will be noted.
A second approach assigns a posted speed to a right of way based on what type of right of way it is. For example, when speaking of automobiles, right-of-ways are roads of differing types, with individually assigned speeds. Examples include a highway at 55 mph, a local highway at 40 mph, primary/secondary streets at 35 mph, or a local street at 25 mph. Such an approach may be more accurate than the prior approach, but is still inaccurate because a highway may have a posted speed that differs from 55 mph, as may the other road types. In this approach as well, speeding exceptions may be missed, (i.e. false negatives), and instances of non-speeding may be recorded as a speeding exception, (i.e. a false positive). Consequently, there remains a need in the art for a way to accurately assess speeding exceptions.